ceph: fix f_namelen reported by statfs

We were setting f_namelen in kstatfs to PATH_MAX instead of NAME_MAX.
That disagrees with ceph_lookup behavior (which checks against NAME_MAX),
and also makes the pjd posix test suite spit out ugly errors because with
can't clean up its temporary files.
Signed-off-by: Sage Weil <sage@newdream.net>

fs/ceph/super.c

@@ -89,7 +89,7 @@ static int ceph_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 	buf->f_files = le64_to_cpu(st.num_objects);
 	buf->f_ffree = -1;
-	buf->f_namelen = PATH_MAX;
+	buf->f_namelen = NAME_MAX;
 	buf->f_frsize = PAGE_CACHE_SIZE;
 
 	/* leave fsid little-endian, regardless of host endianness */